Multi-codeword transmission method and apparatus

ABSTRACT

This application discloses a multi-codeword transmission method and an apparatus. The method includes: generating, by a network device, downlink control information corresponding to each of a plurality of code words to be sent to a terminal device, where the downlink control information corresponding to each code word includes at least one of the following: a physical downlink shared channel resource element mapping and quasi-co-location indicator, and an antenna port(s), scrambling identity and number of layers; and sending, by the network device, downlink control information corresponding to the plurality of code words to the terminal device. Corresponding apparatuses are further disclosed. According to the technical solutions of this application, the network device generates the downlink control information corresponding to each of the plurality of code words to be sent to the terminal device, and the terminal device may demodulate data for the plurality of code words based on downlink control information corresponding to the plurality of code words. This ensures that the terminal device correctly demodulates data in a multi-codeword transmission scenario.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/539,825, filed on Aug. 13, 2019, which is a continuation ofInternational Application No. PCT/CN2018/073736, filed on Jan. 23, 2018,which claims priority to Chinese Patent Application No. 201710087121.8,filed on Feb. 17, 2017. All of the afore-mentioned patent applicationsare hereby incorporated by reference in their entireties.

TECHNICAL FIELD

This application relates to the field of communications technologies,and in particular, to a multi-codeword transmission method and anapparatus.

BACKGROUND

As a long term evolution-advanced (LTE-A) requirement is proposed,people pay increasing attention to cell average spectral efficiency andcell edge spectral efficiency. In both an upstream and a downstream ofan LTE-A system, there are frequency division systems that useorthogonal frequency division multiplexing (OFDM) as a basic multipleaccess multiplexing mode. There is almost no interference problem insidea cell because of complete orthogonal frequency division, butinterference processing at an edge of the cell is relatively difficult.

To improve cell edge spectral efficiency, a non-coherent jointtransmission (NCJT) transmission mode is proposed. NCJT means that aplurality of transmission nodes serve one terminal device at a sametime, that is, the terminal device may receive data from the pluralityof transmission nodes at the same time. Transmission between twotransmission points (TP) is used as an example. In a schematic diagramof coordinated multipoint transmission/reception shown in FIG. 1 , afirst code word (Code Word 1, CW 1), or referred to as a transportblock, is transmitted to a terminal device through a TP 1, and a secondcode word CW 2 is transmitted to the terminal device through a TP 2.Since strict synchronization among a plurality of transmission nodes isnot required, and user experience can be improved through jointtransmission performed by the plurality of transmission nodes, thistransmission technology as a main transmission mode of furtherenhancements to coordinated multipoint operation (Fe-CoMP) has drawnextensive attention and has been widely discussed.

However, in prior-art LTE and LTE-A technologies, one terminal devicereceives only one or more code words from one transmission node at asame time.

Therefore, a problem that a terminal device cannot correctly demodulatedata in a multi-codeword transmission scenario needs to be resolvedurgently.

SUMMARY

This application provides a multi-codeword transmission method and anapparatus, to resolve a problem that a terminal device cannot correctlydemodulate data in a multi-codeword transmission scenario.

According to an aspect, a multi-codeword transmission method isprovided, including: generating, by a network device, downlink controlinformation corresponding to each of a plurality of code words to besent to a terminal device, where the downlink control informationcorresponding to each code word includes at least one of the following:a physical downlink shared channel (PDSCH) resource element mapping andquasi-co-location indicator, and an antenna port(s), scrambling identityand number of layers; and sending, by the network device, downlinkcontrol information corresponding to the plurality of code words to theterminal device. The network device generates the downlink controlinformation corresponding to each of the plurality of code words to besent to the terminal device, and the terminal device may demodulate databased on the downlink control information corresponding to the pluralityof code words. This ensures that the terminal device correctlydemodulates data in a multi-codeword transmission scenario.

According to another aspect, a multi-codeword transmission method isprovided, including: receiving, by a terminal device, downlink controlinformation that is corresponding to a plurality of code words and thatis from a network device, where in the downlink control informationcorresponding to the plurality of code words, downlink controlinformation corresponding to each code word includes at least one of thefollowing: a physical downlink shared channel (PDSCH) resource elementmapping and quasi-co-location indicator, and an antenna port(s),scrambling identity and number of layers; and demodulating, by theterminal device, data based on the downlink control informationcorresponding to the plurality of code words. The terminal devicereceives the downlink control information that is corresponding to eachof the plurality of code words and that is generated by the networkdevice, and may demodulate the data based on the downlink controlinformation corresponding to the plurality of code words. This ensurescorrect data demodulation.

According to still another aspect, a multi-codeword transmission methodis provided, including: generating, by a network device, downlinkcontrol information corresponding to each of a plurality of code wordsto be sent to a terminal device, where the downlink control informationcorresponding to each code word includes: a physical downlink sharedchannel (PDSCH) resource element mapping and quasi-co-locationindicator, and the PDSCH resource element mapping and quasi-co-locationindicator carries at least one of an antenna port, a scramblingidentity, and a quantity of layers; and sending, by the network device,downlink control information corresponding to the plurality of codewords to the terminal device. The network device generates the downlinkcontrol information corresponding to each of the plurality of code wordsto be sent to the terminal device, and the terminal device maydemodulate data based on the downlink control information correspondingto the plurality of code words. This ensures that the terminal devicecorrectly demodulates data in a multi-codeword transmission scenario.

According to still another aspect, a multi-codeword transmission methodis provided, including: receiving, by a terminal device, downlinkcontrol information that is corresponding to a plurality of code wordsand that is from a network device, where in the downlink controlinformation corresponding to the plurality of code words, downlinkcontrol information corresponding to each code word includes: a physicaldownlink shared channel (PDSCH) resource element mapping andquasi-co-location indicator, and the PDSCH resource element mapping andquasi-co-location indicator carries at least one of an antenna port, ascrambling identity, and a quantity of layers; and demodulating, by theterminal device, data based on the downlink control informationcorresponding to the plurality of code words. The terminal devicereceives the downlink control information that is corresponding to eachof the plurality of code words and that is generated by the networkdevice, and may demodulate the data based on the downlink controlinformation corresponding to the plurality of code words. This ensurescorrect data demodulation.

In an embodiment of the foregoing aspects, the downlink controlinformation corresponding to each code word further includes at leastone of the following: a modulation and coding scheme (MCS), a new dataindicator (NDI), and a redundancy version (RV). In this implementation,the downlink control information corresponding to each code word mayfurther include another parameter. The MCS is used to provideinformation related to a modulation mode, an encoding rate, and atransport block size to the terminal device. The NDI is used to empty asoft buffer for initial transmission. The RV is used to provideredundancy version information.

In another embodiment of the foregoing aspects, the PDSCH resourceelement mapping and quasi-co-location indicator includes at least one ofthe following parameters: a PDSCH start point, a multicast-broadcastsingle-frequency network (MBSFN) subframe configuration, a beammanagement reference signal configuration, and a channel stateinformation-reference signal (CSI-RS) configuration. In thisimplementation, the parameters included in the PDSCH resource elementmapping and quasi-co-location indicator are described in detail.

In still another embodiment of the foregoing aspects, the PDSCH resourceelement mapping and quasi-co-location indicator carries at least one ofan antenna port, a scrambling identity, and a quantity of layers.

In still another embodiment of the foregoing aspects, the antenna portincludes a demodulation reference signal (DMRS) port, the scramblingidentity includes DMRS scrambling information, and the quantity oflayers includes a quantity of DMRS layers.

According to still another aspect, a network device is provided. Thenetwork device has a function of implementing behavior of the networkdevice in the foregoing methods. The function may be implemented byhardware, or may be implemented by hardware by executing correspondingsoftware. The hardware or software includes one or more modulescorresponding to the foregoing function.

In an embodiment, the network device includes: a processing unit,configured to generate downlink control information corresponding toeach of a plurality of code words to be sent to a terminal device, wherethe downlink control information corresponding to each code wordincludes at least one of the following: a physical downlink sharedchannel (PDSCH) resource element mapping and quasi-co-locationindicator, and an antenna port(s), scrambling identity and number oflayers; and a sending unit, configured to send downlink controlinformation corresponding to the plurality of code words to the terminaldevice.

In another embodiment, the network device includes a transceiver, amemory, and a processor. The memory stores a group of program code, andthe processor is configured to invoke the program code stored in thememory to perform the following operations: generating downlink controlinformation corresponding to each of a plurality of code words to besent to a terminal device, where the downlink control informationcorresponding to each code word includes at least one of the following:a physical downlink shared channel (PDSCH) resource element mapping andquasi-co-location indicator, and an antenna port(s), scrambling identityand number of layers; and sending, by using the transceiver, thedownlink control information corresponding to the plurality of codewords to the terminal device.

Based on an inventive concept the same as that of the foregoing method,for a principle for resolving a problem by the apparatus and abeneficial effect brought by the apparatus, refer to the foregoingembodiments of the method performed by the network device and beneficialeffects brought by the embodiments. Therefore, for implementation of theapparatus, refer to the implementation of the method, and repeatedcontent is not described again.

According to still another aspect, a terminal device is provided. Theterminal device has a function of implementing behavior of the terminaldevice in the foregoing methods. The function may be implemented byhardware, or may be implemented by hardware by executing correspondingsoftware. The hardware or software includes one or more modulescorresponding to the foregoing function.

In an embodiment, the terminal device includes: a receiving unit,configured to receive downlink control information that is correspondingto a plurality of code words and that is from a network device, where inthe downlink control information corresponding to the plurality of codewords, downlink control information corresponding to each code wordincludes at least one of the following: a physical downlink sharedchannel (PDSCH) resource element mapping and quasi-co-locationindicator, and an antenna port(s), scrambling identity and number oflayers; and a demodulation unit, configured to demodulate data based onthe downlink control information corresponding to the plurality of codewords.

In another embodiment, the terminal device includes a transceiver, amemory, and a processor. The memory stores a group of program code, andthe processor is configured to invoke the program code stored in thememory to perform the following operations: receiving, by using thetransceiver, downlink control information that is corresponding to aplurality of code words and that is from a network device, where in thedownlink control information corresponding to the plurality of codewords, downlink control information corresponding to each code wordincludes at least one of the following: a physical downlink sharedchannel (PDSCH) resource element mapping and quasi-co-locationindicator, and an antenna port(s), scrambling identity and number oflayers; and demodulating data based on the downlink control informationcorresponding to the plurality of code words.

Based on an inventive concept the same as that of the foregoing method,for a principle for resolving a problem by the apparatus and abeneficial effect brought by the apparatus, refer to the foregoingembodiments of the method performed by the terminal device andbeneficial effects brought by the embodiments. Therefore, forimplementation of the apparatus, refer to the implementation of themethod, and repeated content is not described again.

According to still another aspect, a network device is provided. Thenetwork device has a function of implementing behavior of the networkdevice in the foregoing methods. The function may be implemented byhardware, or may be implemented by hardware by executing correspondingsoftware. The hardware or software includes one or more modulescorresponding to the foregoing function. In an embodiment, the networkdevice includes: a processing unit, configured to generate downlinkcontrol information corresponding to each of a plurality of code wordsto be sent to a terminal device, where the downlink control informationcorresponding to each code word includes: a physical downlink sharedchannel (PDSCH) resource element mapping and quasi-co-locationindicator, and the PDSCH resource element mapping and quasi-co-locationindicator carries at least one of an antenna port, a scramblingidentity, and a quantity of layers; and a sending unit, configured tosend downlink control information corresponding to the plurality of codewords to the terminal device.

In another embodiment, the network device includes a transceiver, amemory, and a processor. The memory stores a group of program code, andthe processor is configured to invoke the program code stored in thememory to perform the following operations: generating downlink controlinformation corresponding to each of a plurality of code words to besent to a terminal device, where the downlink control informationcorresponding to each code word includes: a physical downlink sharedchannel (PDSCH) resource element mapping and quasi-co-locationindicator, and the PDSCH resource element mapping and quasi-co-locationindicator carries at least one of an antenna port, a scramblingidentity, and a quantity of layers; and sending, by using thetransceiver, the downlink control information corresponding to theplurality of code words to the terminal device.

Based on an inventive concept the same as that of the foregoing method,for a principle for resolving a problem by the apparatus and abeneficial effect brought by the apparatus, refer to the foregoingembodiments of the method performed by the network device and beneficialeffects brought by the implementations. Therefore, for implementation ofthe apparatus, refer to the implementation of the method, and repeatedcontent is not described again.

According to still another aspect, a terminal device is provided. Theterminal device has a function of implementing behavior of the terminaldevice in the foregoing methods. The function may be implemented byhardware, or may be implemented by hardware by executing correspondingsoftware. The hardware or software includes one or more modulescorresponding to the foregoing function.

In an embodiment, the terminal device includes: a receiving unit,configured to receive downlink control information that is correspondingto a plurality of code words and that is from a network device, where inthe downlink control information corresponding to the plurality of codewords, downlink control information corresponding to each code wordincludes at least one of the following: a physical downlink sharedchannel (PDSCH) resource element mapping and quasi-co-locationindicator, and the PDSCH resource element mapping and quasi-co-locationindicator carries at least one of an antenna port, a scramblingidentity, and a quantity of layers; and a demodulation unit, configuredto demodulate data based on the downlink control informationcorresponding to the plurality of code words.

In another embodiment, the terminal device includes a transceiver, amemory, and a processor. The memory stores a group of program code, andthe processor is configured to invoke the program code stored in thememory to perform the following operations: receiving, by using thetransceiver, downlink control information that is corresponding to aplurality of code words and that is from a network device, where in thedownlink control information corresponding to the plurality of codewords, downlink control information corresponding to each code wordincludes at least one of the following: a physical downlink sharedchannel (PDSCH) resource element mapping and quasi-co-locationindicator, and the PDSCH resource element mapping and quasi-co-locationindicator carries at least one of an antenna port, a scramblingidentity, and a quantity of layers; and demodulating data based on thedownlink control information corresponding to the plurality of codewords.

Based on an inventive concept the same as that of the foregoing method,for a principle for resolving a problem by the apparatus and abeneficial effect brought by the apparatus, refer to the foregoingembodiments of the method performed by the terminal device andbeneficial effects brought by the implementations. Therefore, forimplementation of the apparatus, refer to the implementation of themethod, and repeated content is not described again.

Still another aspect of this application provides a computer readablestorage medium, where the computer readable storage medium stores aninstruction, and when the instruction runs on a computer, the computeris enabled to perform the methods in the foregoing aspects.

Yet another aspect of this application provides a computer programproduct including an instruction, where when the instruction runs on acomputer, the computer performs the method in the foregoing aspects.

BRIEF DESCRIPTION OF DRAWINGS

To describe the technical solutions in embodiments of the presentdisclosure or in the background more clearly, the following describesthe accompanying drawings required for describing the embodiments of thepresent disclosure or the background.

FIG. 1 is a schematic diagram of an example of coordinated multipointtransmission/reception;

FIG. 2 a to FIG. 2 c are schematic diagrams of a plurality of possiblephysical downlink shared channel resource element mappings;

FIG. 3 is a schematic interaction diagram of a multi-codewordtransmission method according to an embodiment of the presentdisclosure;

FIG. 4 is a schematic module diagram of a network device according to anembodiment of the present disclosure;

FIG. 5 is a schematic module diagram of a terminal device according toan embodiment of the present disclosure;

FIG. 6 is a schematic architectural diagram of hardware of a networkdevice according to an embodiment of the present disclosure; and

FIG. 7 is a schematic architectural diagram of hardware of a terminaldevice according to an embodiment of the present disclosure.

DESCRIPTION OF EMBODIMENTS

The following describes the embodiments of the present disclosure withreference to accompanying drawings in the embodiments of the presentdisclosure.

A communications system in the embodiments of the present disclosureincludes a network device and a terminal device. The network devicecontrols multi-codeword transmission of a transmission node. Thecommunications system may be a global system for mobile communications(GSM) system, a code division multiple access (CDMA) system, a widebandcode division multiple access (WCDMA) system, a worldwideinteroperability for microwave access (WiMAX) system, a long termevolution (LTE) system, a 5G communications system (for example, a newradio (NR) system), a communications system that integrates variouscommunications technologies (for example, a communications system thatintegrates an LTE technology and an NR technology), or a subsequentevolved communications system.

The terminal device in this application is a device having a wirelesscommunication function. The terminal device may be a handheld device, anin-vehicle device, a wearable device, or a computing device that has thewireless communication function, another processing device connected toa wireless modem, or the like. In different networks, the terminaldevice may have different names such as user equipment (UE), an accessterminal, a subscriber unit, a subscriber station, a mobile station, amobile console, a remote station, a remote terminal, a mobile device, asubscriber terminal, a terminal, a wireless communications device, auser agent or a user apparatus, a cellular phone, a cordless telephoneset, a session initiation protocol (SIP) phone, a wireless local loop(WLL) station, a personal digital assistant (PDA), or a terminal devicein a 5G network or a future evolved network.

The network device in this application is a device that is deployed in aradio access network to provide a wireless communication function. Thenetwork device includes but is not limited to: a base station (forexample, a Base Transceiver Station (BTS), a NodeB (NB), an evolvedNodeB (Evolutional Node B, eNB or eNodeB), a transmission node (forexample, a transmission/reception point (TRP) or a transmission point(TP) in an NR system, or a next-generation NodeB (generation nodeB,gNB), a base station or a network device in a future communicationsnetwork, a relay node, an access point, an in-vehicle device, a wearabledevice, a wireless fidelity (Wi-Fi) site, a wireless backhaul node, asmall cell, a micro cell, and the like. In existing LTE and LTE-Aprotocols, a downlink control channel corresponds to one or two codewords during coordinated multipoint transmission/reception (CoMP). Whena downlink control channel carries scheduling information of a pluralityof code words, by default in a system, a plurality of code words carriedon a physical downlink shared channel (PDSCH) are from one transmissionnode or from a plurality of transmission nodes synchronized with eachother in time/frequency domain. In other words, the plurality of codewords have a same large-scale channel experience. The large-scalechannel experience includes the following features: delay spread (delayspread), Doppler spread, Doppler shift, an average gain, an averagedelay, a receive beam number of a terminal device, a transmit/receivechannel correlation, a received angle of arrival (AoA), a spatialcorrelation of a receiver antenna, a primary angle of arrival, anaverage angle of arrival, AoA spread, and the like. However, in downlinkcontrol information, only one set of the following parameters isincluded: a physical downlink shared channel resource element (PDSCH RE)mapping and quasi-co-location indicator, and an antenna port(s),scrambling identity and number of layers.

For multi-codeword transmission performed in an NCJT scenario, differentcode words are transmitted by different transmission nodes; and eachtransmission node separately performs self-adaptive precoding, that is,a plurality of code words correspond to different large-scale channelexperiences, and time/frequency domain resources carried by theplurality of code words may be different. If demodulation of theplurality of code words is implemented according to an existing protocolby using one set of parameters of the PDSCH resource element mapping andquasi-co-location indicator, a high bit error rate of data transmissionis caused. Therefore, in actual transmission, downlink controlinformation matching a PDSCH for each transmission node should beconsidered. In addition, fixed information about an antenna port(s),scrambling identity and number of layers does not match a decodingrequirement of all transmission nodes either. A PDSCH resource elementmapping is used as an example. As shown in FIG. 2 a to FIG. 2 c , actualPDSCH resource element mapping information carried in different codewords may be exactly the same (as shown in FIG. 2 a ), partially thesame (as shown in FIG. 2 b ), or even completely different (as shown inFIG. 2 c ). Therefore, existing configuration information cannot ensurethat downlink control information such as a PDSCH resource elementmapping and quasi-co-location indicator, and an antenna port(s),scrambling identity and number of layers matches that of alltransmission nodes in a case of multi-codeword transmission performed inthe NCJT scenario.

The embodiments of the present disclosure provide a multi-codewordtransmission method and an apparatus. A network device generatesdownlink control information corresponding to each of a plurality ofcode words to be sent to a terminal device, and the terminal device maydemodulate data based on the downlink control information correspondingto the plurality of code words. This ensures that the terminal devicecorrectly demodulates data in a multi-codeword transmission scenario.

Multi-codeword transmission scenarios in the embodiments of the presentdisclosure include: coordinated multipoint transmission/reception, forexample, NCJT; multi-codeword transmission performed by using aplurality of beam groups used for one transmission node, for example,high frequency communication based on a plurality of simulated narrowbeams; and multi-codeword transmission performed by using differentantenna panels used for one transmission node, for example, highfrequency communication based on a plurality of panels (multiplepanels).

FIG. 3 is a schematic interaction diagram of a multi-codewordtransmission method according to an embodiment of the presentdisclosure. The method includes the following operations:

S101. A network device generates downlink control informationcorresponding to each of a plurality of code words to be sent to aterminal device.

In this embodiment, the plurality of code words may be from a pluralityof transmission nodes, for example, a plurality of code words used inNCJT in coordinated multi-point transmission/reception; may be from aplurality of beam groups used for one transmission node, for example, aplurality of code words used in high frequency communication that isbased on a plurality of simulated narrow beams; or may be from differentantenna panels used for one transmission node, for example, a pluralityof code words in high frequency communication based on multiple panels.Optionally, the terminal device may be one terminal device or differentterminal devices. In this embodiment, before the plurality oftransmission nodes, the plurality of beam groups used for onetransmission node, or the different antenna panels used for onetransmission node send code words, the network device generates thedownlink control information (DCI) corresponding to each of theplurality of code words to be sent to the terminal device. The downlinkcontrol information corresponding to each code word includes at leastone of the following: a PDSCH resource element mapping andquasi-co-location indicator, and an antenna port(s), scrambling identityand number of layers. Optionally, the downlink control informationcorresponding to each code word includes the PDSCH resource elementmapping and quasi-co-location indicator, and the antenna port(s),scrambling identity and number of layers.

The PDSCH mapping and quasi-co-location indicator is used to indicate aquasi-co-location relationship between antenna ports, and corresponds toa quasi-co-location relationship between reference signals of differenttypes. The PDSCH resource element mapping and quasi-co-locationindicator includes at least one of the following parameters: a PDSCHstart point, a multicast-broadcast single-frequency network (MBSFN)subframe configuration, a beam management reference signalconfiguration, and a channel state information-reference signal (CSI-RS)configuration. Herein, the reference signals of different types includea beam management reference signal, a CSI-RS, and a demodulationreference signal (DMRS). The beam management reference signal is used tomeasure a simulated beam, the CSI-RS is used to measure channel stateinformation, and the DMRS is used to demodulate data. The beammanagement reference signal, the CSI-RS, and the DMRS have aquasi-co-location relationship. This means that one transmission node,one beam group of the same transmission node, or a group of antennaports of one antenna panel of the transmission node have a samelarge-scale channel feature. Different transmission points, differentbeam groups, or different antenna panels that send a plurality of codewords correspond to at least two groups of antenna ports. Large-scalechannel features may include delay spread, an average delay, Dopplerspread, Doppler shift, an average gain, a receive beam number of aterminal device, a transmit/receive channel correlation, a receivedangle of arrival, a spatial correlation of a receiver antenna, a primaryangle of arrival, an average angle of arrival, AoA spread, and the like.A quasi-co-location indicator is used to indicate whether at least twogroups of antenna ports have a quasi-co-location relationship asfollows: The quasi-co-location indicator is used to indicate whetherreference signals sent by the at least two groups of antenna ports arefrom one transmission point; the quasi-co-location indicator is used toindicate whether reference signals sent by the at least two groups ofantenna ports are from one beam group; or the quasi-co-locationindicator is used to indicate whether reference signals sent by the atleast two groups of antenna ports are from one antenna panel.

The antenna port(s), scrambling identity and number of layers is used toindicate a DMRS port, a DMRS scrambling identity, and a quantity of DMRSlayers that correspond to a current code word. In an LTE protocol, arelationship between a DMRS port number and a quantity of DMRS transportlayers is: a UE-specific reference signal related to a PDSCH istransmitted from the following antenna ports: p=5, p=7, p=8, p=11, p=13,p={11, 13}, or p=7, 8, . . . , v+6, where v is the quantity of transportlayers used for a PDSCH. The DMRS scrambling identity is used todetermine a DMRS sending sequence. For detailed definition andapplication of this parameter, refer to the LTE protocol, and detailsare not described herein again one by one.

The two parameters, the PDSCH resource element mapping andquasi-co-location indicator and the antenna port(s), scrambling identityand number of layers, are closely related to a code word. If a pluralityof code words are transmitted, and the plurality of code words are fromdifferent transmission nodes, different beam groups, or differentantenna panels, and when a set of the two parameters is used for theplurality of code words, data demodulation fails.

Further, the downlink control information corresponding to each codeword further includes at least one of the following: a modulation andcoding scheme (Modulation and Coding Scheme, MCS), a new data indicator(NDI), and a redundancy version (RV). The MCS is used to provideinformation related to a modulation mode, an encoding rate, and atransport block size to the terminal device. The NDI is used to empty asoft buffer for initial transmission. For detailed definition andapplication of these parameters, refer to the LTE protocol, and detailsare not described herein again one by one.

In addition to the downlink control information corresponding to eachcode word, downlink control information may further include moreparameters. The following parameters may be transmitted in a DCI 2Dformat according to the existing LTE protocol. The downlink controlinformation is used by the terminal device to demodulate data. Anexample in which two TPs transmit two codes words for one UE at a sametime is provided, and a case in which more than two code words aretransmitted is excluded. The DCI sent by the two TPs includes:

-   -   a carrier indicator, indicating a component carrier to which the        downlink control information is related;    -   a resource allocation header (a resource allocation type 0/1);    -   a resource block allocation, indicating a resource block on a        component carrier on which the terminal device should receive a        PDSCH;    -   a transmit power control (TPC) command for a physical uplink        control channel (PUCCH), used to schedule secondary carriers in        carrier aggregation.    -   a downlink assignment index, used to inform the terminal device        of information related to a quantity of downlink transmissions;    -   a quantity of hybrid automatic repeat request (HARQ) processes,        used to inform the terminal device of a related current HARQ        process;    -   a sounding reference signal (SRS) request, only used in time        division duplexing (TDD) to trigger transmission of an uplink        sounding reference signal;    -   a first code word;    -   a MCS;    -   an NDI;    -   an RV;    -   a PDSCH resource element mapping and quasi-co-location        indicator;    -   an antenna port(s), scrambling identity and number of layers;    -   a second code word;    -   a MCS;    -   an NDI;    -   an RV;    -   a PDSCH resource element mapping and quasi-co-location        indicator;    -   an antenna port(s), scrambling identity and number of layers;        and    -   a HARQ-ACK resource offset (used for an enhanced physical        downlink control channel ePDCCH), used to dynamically control a        PUCCH resource that is for a HARQ acknowledgment.

In an embodiment, the PDSCH resource element mapping andquasi-co-location indicator, and the antenna port(s), scramblingidentity and number of layers may be included in one parameter set, orincluded in different parameter sets. In an optional manner, the twoparameters, the PDSCH resource element mapping and quasi-co-locationindicator, and the antenna port(s), scrambling identity and number oflayers, are included in different parameter sets, that is, the twoparameters are represented by using parameter sets of two domains. Forexample, in the foregoing DCI parameter that is used as an example, thetwo parameters are separately represented. In another optional manner,the two parameters, the PDSCH resource element mapping andquasi-co-location indicator, and the antenna port(s), scramblingidentity and number of layers, are included in one parameter set, thatis, the two parameters are represented by using a parameter set of onedomain. In other words, the PDSCH resource element mapping andquasi-co-location indicator carries an antenna port, a scramblingidentity, and a quantity of layers. The PDSCH resource element mappingand quasi-co-location indicator includes at least one of the followingparameters: a PDSCH start point, a multicast-broadcast single-frequencynetwork subframe configuration, a beam management reference signalconfiguration, and a channel state information-reference signalconfiguration, a DMRS port, a DMRS scrambling information, and aquantity of DMRS layers.

S102. The network device sends downlink control informationcorresponding to the plurality of code words to the terminal device.

The network device may send, through a physical downlink control channel(PDCCH), the downlink control information corresponding to the pluralityof code words to the terminal device. Alternatively, the network devicemay send, through a plurality of PDCCHs, the downlink controlinformation corresponding to the plurality of code words to the terminaldevice. The terminal device receives the downlink control informationthat is corresponding to the plurality of code words and that is fromthe network device.

S103. The terminal device demodulates data based on the downlink controlinformation corresponding to the plurality of code words.

As the terminal device receives the downlink control informationcorresponding to each code word, the downlink control informationcorresponding to the plurality of code words may be used to demodulatethe data for the plurality of code words that are from differenttransmission nodes, different beam groups of one transmission node, ordifferent antenna panels of one transmission node. For a specific datademodulation process, refer to an existing LTE protocol, and details arenot described herein again.

According to the multi-codeword transmission method provided in thisembodiment of the present disclosure, the network device generates thedownlink control information corresponding to each of the plurality ofcode words to be sent to the terminal device, and the terminal devicemay demodulate data for the plurality of code words based on thedownlink control information corresponding to the plurality of codewords. This ensures that the terminal device correctly demodulates datain a multi-codeword transmission scenario.

The foregoing describes in detail the method in the embodiments of thepresent disclosure, and the following provides the apparatuses in theembodiments of the present disclosure.

FIG. 4 is a schematic module diagram of a network device according to anembodiment of the present disclosure. The network device 1000 mayinclude a processing unit 11 and a sending unit 12. The processing unit11 may be configured to control an operation of the network device, forexample, perform S101 of generating downlink control informationcorresponding to each of a plurality of code words to be sent to aterminal device. The sending unit 12 may be configured to communicatewith the terminal device, for example, perform S102 of sending thedownlink control information corresponding to the plurality of codewords to the terminal device. For details, refer to the description inthe method embodiment, and details are not described herein again.

According to the network device provided in this embodiment of thepresent disclosure, the network device generates the downlink controlinformation corresponding to each of the plurality of code words to besent to the terminal device, and the terminal device may performdemodulation, based on the downlink control information corresponding toeach code word, for the plurality of code words that are from differenttransmission nodes. This ensures correct demodulation.

FIG. 5 is a schematic module diagram of a terminal device according toan embodiment of the present disclosure. The terminal device 2000 mayinclude a receiving unit 21 and a demodulation unit 22. The receivingunit 21 may be configured to communicate with a network device, forexample, receive, after S102 is performed, the downlink controlinformation that is corresponding to the plurality of code words andthat is from the network device. The demodulation unit 22 may beconfigured to control an operation of the terminal device, for example,perform S103 of demodulating data based on the downlink controlinformation corresponding to the plurality of code words. For details,refer to the description in the method embodiment, and details are notdescribed herein again.

According to the terminal device provided in this embodiment of thepresent disclosure, the terminal device receives the downlink controlinformation that is corresponding to each of the plurality of code wordsand that is generated by the network device, and may demodulate the datafor the plurality of code words based on the downlink controlinformation corresponding to the plurality of code words. This ensuresthat the terminal device correctly demodulates data in a multi-codewordtransmission scenario.

FIG. 6 is an architectural diagram of hardware of a network deviceaccording to an embodiment of the present disclosure. The network device3000 may include a transceiver 31, a processor 32, and a memory 33. Thetransceiver 31, the processor 32, and the memory 33 are connected toeach other by using a bus 34. A related function implemented by theprocessing unit 11 in FIG. 4 may be implemented by one or moreprocessors 32, and a related function implemented by the sending unit 12in FIG. 4 may be implemented by the transceiver 31.

The memory 33 includes but is not limited to a random access memory ( ),a read-only memory (ROM), an erasable programmable read only memory(EPROM), or a compact disc read-only memory (CD-ROM). The memory 33 isconfigured to store a related instruction and data.

The transceiver 31 is configured to send data and/or a signal andreceive data and/or a signal. The transceiver 31 may include atransmitter and a receiver. The transmitter and the receiver perform asending operation and a receiving operation, respectively. Thetransmitter and the receiver may be independent components, or may be anintegral component.

The processor 32 may include one or more processors, for example,include one or more central processing units (CPU). When the processor32 is one CPU, the CPU may be a single-core CPU, or may be a multi-coreCPU.

The processor 33 is configured to support the network device inperforming operation S101, shown in FIG. 3 , of generating downlinkcontrol information corresponding to each of a plurality of code wordsto be sent to a terminal device. The memory 33 is configured to storeprogram code and data of the network device.

The transceiver 31 is configured to communicate with the terminaldevice, and perform operation S102, shown in FIG. 3 , of sending thedownlink control information corresponding to the plurality of codewords to the terminal device.

For details about operations performed by the processor 33 and thetransceiver 31, refer to descriptions of the embodiment shown in FIG. 3, and details are not described herein again.

It is understood that FIG. 6 shows only a simplified design of thenetwork device. In an actual application, each network device mayfurther include another necessary component that includes but is notlimited to: any quantity of transceivers, any quantity of processors,any quantity of controllers, and any quantity of memories. In addition,all network devices that can implement the present disclosure fall inthe protection scope of the present disclosure.

According to the network device provided in this embodiment of thepresent disclosure, the network device generates the downlink controlinformation corresponding to each of the plurality of code words to besent to the terminal device, and the terminal device may demodulate datafor the plurality of code words based on the downlink controlinformation corresponding to the plurality of code words. This ensuresthat the terminal device correctly demodulates data in a multi-codewordtransmission scenario.

FIG. 7 is a schematic architectural diagram of hardware of a terminaldevice according to an embodiment of the present disclosure. Theterminal device 4000 may include a transceiver 41, a processor 42, and amemory 43. The transceiver 41, the processor 42, and the memory 43 areconnected to each other by using a bus 44. A related functionimplemented by the demodulation unit 22 in FIG. 5 may be implemented byone or more processors 42, and a related function implemented by thereceiving unit 21 in FIG. 5 may be implemented by the transceiver 41.

The memory 43 includes but is not limited to a random access memory, aread-only memory, an erasable programmable read only memory, or acompact disc read-only memory. The memory 43 is configured to store arelated instruction and data.

The transceiver 41 is configured to send data and/or a signal andreceive data and/or a signal. The transceiver 41 may include atransmitter and a receiver. The transmitter and the receiver perform asending operation and a receiving operation, respectively. Thetransmitter and the receiver may be independent components, or may be anintegral component.

The processor 42 may include one or more processors, for example,include one or more central processing units. When the processor 42 isone CPU, the CPU may be a single-core CPU, or may be a multi-core CPU.

The processor 43 is configured to support the terminal device inperforming operation S103, shown in FIG. 3 , of demodulating data basedon the downlink control information corresponding to the plurality ofcode words. The memory 43 is configured to store program code and dataof the terminal device.

The transceiver 41 is configured to: communicate with the terminaldevice, perform operation S102 shown in FIG. 3 , and receive thedownlink control information that is corresponding to the plurality ofcode words and that is from the network device.

For details about operations performed by the processor 43 and thetransceiver 41, refer to descriptions of the embodiment shown in FIG. 3, and details are not described herein again.

It is understood that FIG. 7 shows only a simplified design of theterminal device. In an actual application, each terminal device mayfurther include another necessary component that includes but is notlimited to: any quantity of transceivers, any quantity of processors,any quantity of controllers, and any quantity of memories. In addition,all terminal devices that can implement the present disclosure fall inthe protection scope of the present disclosure.

According to the terminal device provided in this embodiment of thepresent disclosure, the terminal device receives the downlink controlinformation that is corresponding to each of the plurality of code wordsand that is generated by the network device, and may demodulate data forthe plurality of code words based on the downlink control informationcorresponding to the plurality of code words. This ensures that theterminal device correctly demodulates data in a multi-codewordtransmission scenario.

A person of ordinary skill in the art may be aware that, the units andalgorithm operations in the examples described with reference to theembodiments disclosed in this specification may be implemented byelectronic hardware or a combination of computer software and electronichardware. Whether the functions are performed by hardware or softwaredepends on particular applications and design constraints of thetechnical solutions. A person skilled in the art may use differentmethods to implement the described functions for each particularapplication, but it should not be considered that the implementationgoes beyond the scope of this application.

It is understood by a person skilled in the art that, for the purpose ofconvenient and brief description, for a detailed working process of thesystem, apparatus, and unit, refer to a corresponding process in themethod embodiments. Details are not described herein again.

In the several embodiments provided in this application, it isunderstood that the disclosed system, apparatus, and method may beimplemented in other manners. For example, the described apparatusembodiment is merely an example. For example, the unit division ismerely logical function division and may be other division in actualimplementation. For example, a plurality of units or components may becombined or integrated into another system, or some features may beignored or not performed. In addition, the displayed or discussed mutualcouplings or direct couplings or communication connections may beimplemented by using some interfaces. The indirect couplings orcommunication connections between the apparatuses or units may beimplemented in electrical, mechanical, or other forms.

The units described as separate parts may or may not be physicallyseparate, and parts displayed as units may or may not be physical units,may be located in one position, or may be distributed on a plurality ofnetwork units. Some or all of the units may be selected according toactual needs to achieve the objectives of the solutions of theembodiments.

In addition, functional units in the embodiments of this application maybe integrated into one processing unit, or each of the units may existalone physically, or two or more units are integrated into one unit.

All or some of the foregoing embodiments may be implemented by usingsoftware, hardware, firmware, or any combination thereof. When softwareis used to implement the embodiments, the embodiments may be implementedcompletely or partially in a form of a computer program product. Thecomputer program product includes one or more computer instructions.When the computer program instructions are loaded and executed on thecomputer, the procedures or functions according to the embodiments ofthe present disclosure are all or partially generated. The computer maybe a general-purpose computer, a special-purpose computer, a computernetwork, or another programmable apparatus. The computer instructionsmay be stored in a computer-readable storage medium, or may betransmitted by using the computer-readable storage medium. The computerinstructions may be transmitted from a website, computer, server, ordata center to another website, computer, server, or data center in awired (for example, a coaxial cable, an optical fiber, or a digitalsubscriber line (DSL)) or wireless (for example, infrared, radio, ormicrowave) manner. The computer-readable storage medium may be anyusable medium accessible by a computer, or a data storage device, suchas a server or a data center, integrating one or more usable media. Theusable medium may be a magnetic medium (for example, a floppy disk, ahard disk, or a magnetic tape), an optical medium (for example, a DVD),a semiconductor medium (for example, a solid-state disk (SSD)), or thelike.

The invention claimed is:
 1. A multi-transmission node transmissionmethod, comprising: generating, by a network device, a downlink controlinformation (DCI) corresponding to each of a plurality of transmissionnodes and corresponding to each of a plurality of code words that is tobe sent to a terminal device from a transmission node; scheduling, bythe network device, a physical downlink shared channel (PDSCH)corresponding to each of the plurality of transmission nodes andcorresponding to the DCI; and sending, by the network device, the DCIcorresponding to each of the plurality of transmission nodes to theterminal device, wherein the DCI is used by the terminal device todemodulate data for the code word that is carried on the PDSCHcorresponding to the transmission node with a channel feature comprisingparameters including a received angle of arrival, a primary angle ofarrival, and a received angle of arrival spread.
 2. The method accordingto claim 1, wherein the DCI corresponding to each of the plurality oftransmission nodes comprises at least one of the following: a PDSCHresource element mapping and quasi-co-location indicator, one or moreantenna ports, scrambling identity, or a number of layers.
 3. The methodaccording to claim 2, wherein PDSCH resource element mapping informationin the plurality of transmission nodes is exactly the same, partiallythe same, or completely different.
 4. The method according to claim 2,wherein the quasi-co-location indicator comprises at least one of thefollowing parameters: a beam management reference signal configuration,a channel state information-reference signal (CSI-RS) configuration, ora demodulation reference signal (DMRS).
 5. The method according to claim2, wherein the quasi-co-location indicator indicates whether referencesignals sent by at least two groups of antenna ports of the plurality oftransmission nodes have the same channel feature.
 6. The methodaccording to claim 5, wherein the channel feature further comprising oneor more of following parameters: delay spread, an average delay, Dopplerspread, Doppler shift, an average gain, a receive beam number of theterminal device, a transmit/receive channel correlation, a spatialcorrelation of a receiver antenna, or an average angle of arrival.
 7. Amulti-transmission node transmission method, comprising: receiving, by aterminal device, a downlink control information (DCI) corresponding toeach of a plurality of transmission nodes from a network device andcorresponding to each of a plurality of code words that is to be sent tothe terminal device from a transmission node, wherein the network devicehas scheduled a physical downlink shared channel (PDSCH) correspondingto each of the plurality of transmission nodes and corresponding to theDCI; and demodulating, by the terminal device using the DCIcorresponding to each of the plurality of transmission nodes, data forthe code word carried on the PDSCH corresponding to the transmissionnode with a channel feature comprising parameters including a receivedangle of arrival, a primary angle of arrival, and a received angle ofarrival spread.
 8. The method according to claim 7, wherein the DCIcorresponding to each of the plurality of transmission nodes comprisesat least one of the following: a PDSCH resource element mapping andquasi-co-location indicator, one or more antenna ports, scramblingidentity, or a number of layers.
 9. The method according to claim 8,wherein PDSCH resource element mapping information in the plurality oftransmission nodes is exactly the same, partially the same, orcompletely different.
 10. The method according to claim 8, wherein thequasi-co-location indicator comprises at least one of the followingparameters: a beam management reference signal configuration, a channelstate information-reference signal (CSI-RS) configuration, or ademodulation reference signal (DMRS).
 11. The method according to claim8, wherein the quasi-co-location indicator indicates whether referencesignals sent by at least two groups of antenna ports of the plurality oftransmission nodes have the same channel feature.
 12. A communicationapparatus, comprising: a receiver, configured to receive a downlinkcontrol information (DCI) corresponding to each of a plurality oftransmission nodes from a network device and corresponding to each of aplurality of code words that is to be sent to the communicationapparatus from a transmission node, wherein the network device hasscheduled a physical downlink shared channel (PDSCH) corresponding toeach of the plurality of transmission nodes and corresponding to theDCI; and a processor, configured to demodulate, using the DCIcorresponding to each of the plurality of transmission nodes, data forthe code word carried on the PDSCH corresponding to the transmissionnode with a channel feature comprising parameters including a receivedangle of arrival, a primary angle of arrival, and a received angle ofarrival spread.
 13. The communication apparatus according to claim 12,wherein the DCI corresponding to each of the plurality of transmissionnodes comprises at least one of the following: a PDSCH resource elementmapping and quasi-co-location indicator, one or more antenna ports,scrambling identity, or a number of layers.
 14. The communicationapparatus according to claim 13, wherein PDSCH resource element mappinginformation in the plurality of transmission nodes is exactly the same,partially the same, or completely different.
 15. The communicationapparatus according to claim 13, wherein the quasi-co-location indicatorcomprises at least one of the following parameters: a beam managementreference signal configuration, a channel state information-referencesignal (CSI-RS) configuration, or a demodulation reference signal(DMRS).
 16. The communication apparatus according to claim 13, whereinthe quasi-co-location indicator indicates whether reference signals sentby at least two groups of antenna ports of the plurality of transmissionnodes have the same channel feature.
 17. A communication apparatus,comprising: a processor, configured to: generate a downlink controlinformation (DCI) corresponding to each of a plurality of transmissionnodes and corresponding to each of a plurality of code words that is tobe sent to a terminal device from a transmission node, and schedule aphysical downlink shared channel (PDSCH) corresponding to each of theplurality of transmission nodes and corresponding to the DCI; and atransmitter, configured to send the DCI corresponding to each of theplurality of transmission nodes to the terminal device, wherein the DCIis used by the terminal device to demodulate data for the code word thatis carried on the PDSCH corresponding to the transmission node with achannel feature comprising parameters including a received angle ofarrival, a primary angle of arrival, and a received angle of arrivalspread.
 18. The communication apparatus according to claim 17, whereinthe DCI corresponding to each of the plurality of transmission nodescomprises at least one of the following: a PDSCH resource elementmapping and quasi-co-location indicator, one or more antenna ports,scrambling identity, or a number of layers.
 19. The communicationapparatus according to claim 18, wherein PDSCH resource element mappinginformation in the plurality of transmission nodes is exactly the same,partially the same, or completely different.
 20. The communicationapparatus according to claim 18, wherein the quasi-co-location indicatorcomprises at least one of the following parameters: a beam managementreference signal configuration, a channel state information-referencesignal (CSI-RS) configuration, or a demodulation reference signal(DMRS).
 21. The communication apparatus according to claim 18, whereinthe quasi-co-location indicator indicates whether reference signals sentby at least two groups of antenna ports of the plurality of transmissionnodes have the same channel feature.
 22. The communication apparatusaccording to claim 21, wherein the channel feature further comprisingone or more of following parameters: delay spread, an average delay,Doppler spread, Doppler shift, an average gain, a receive beam number ofthe terminal device, a transmit/receive channel correlation, a spatialcorrelation of a receiver antenna, or an average angle of arrival.